Magnetotail behavior during storm time "sawtooth injections"

[1] A series of magnetic storms occurred during 16 - 21 April 2002 with multiple local minima in the Dst index. During this storm period, Geotail traversed the magnetotail from the premidnight tail lobe in the midtail region to the postmidnight plasma sheet in the near-Earth region. Simultaneous observations of energetic particles at the geostationary altitude showed the feature known as "sawtooth injections'' remarkably well from 18 April to 19 April. This conjunction allows us to examine the magnetotail behavior in the tail lobe and the plasma sheet associated with sawtooth injections. In the tail lobe, close but not perfect time coincidence is found between injection onset and start of southward dipping of the magnetic field vector in the tail lobe. Long-duration (1-2 hours) southward dipping in the tail lobe magnetic field appears to be a global behavior of the tail lobe in association with sawtooth injections. In the plasma sheet, intermittent occurrences of plasma flow reversal from sunward to tailward and of magnetic field from northward to southward are found. The duration of southward magnetic field is typically short (1-5 min) within the plasma sheet. There are some sawtooth injections that are not accompanied by any significant changes in plasma sheet parameters ( plasma flows, magnetic and electric fluctuation levels), suggesting the plasma sheet behavior to be localized even in association with sawtooth injections that are global in nature. There was no indication of the magnetotail being driven in a relatively "steady state'' in association with sawtooth injections during this sequence of storms.